scholarly journals A genome‐wide association study approach to the identification of candidate genes underlying agronomic traits in alfalfa ( Medicago sativa L.)

2019 ◽  
Vol 18 (3) ◽  
pp. 611-613 ◽  
Author(s):  
Zan Wang ◽  
Xuemin Wang ◽  
Han Zhang ◽  
Lin Ma ◽  
Haiming Zhao ◽  
...  
Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 318
Author(s):  
Tae-Ho Ham ◽  
Yebin Kwon ◽  
Yoonjung Lee ◽  
Jisu Choi ◽  
Joohyun Lee

We conducted a genome-wide association study (GWAS) of cold tolerance in a collection of 127 rice accessions, including 57 Korean landraces at the seedling stage. Cold tolerance of rice seedlings was evaluated in a growth chamber under controlled conditions and scored on a 0–9 scale, based on their low-temperature response and subsequent recovery. GWAS, together with principal component analysis (PCA) and kinship matrix analysis, revealed four quantitative trait loci (QTLs) on chromosomes 1, 4, and 5 that explained 16.5% to 18.5% of the variance in cold tolerance. The genomic region underlying the QTL on chromosome four overlapped with a previously reported QTL associated with cold tolerance in rice seedlings. Similarly, one of the QTLs identified on chromosome five overlapped with a previously reported QTL associated with seedling vigor. Subsequent bioinformatic and haplotype analyses revealed three candidate genes affecting cold tolerance within the linkage disequilibrium (LD) block of these QTLs: Os01g0357800, encoding a pentatricopeptide repeat (PPR) domain-containing protein; Os05g0171300, encoding a plastidial ADP-glucose transporter; and Os05g0400200, encoding a retrotransposon protein, Ty1-copia subclass. The detected QTLs and further evaluation of these candidate genes in the future will provide strategies for developing cold-tolerant rice in breeding programs.


2010 ◽  
Vol 125 (2) ◽  
pp. 321-327.e13 ◽  
Author(s):  
Hao Wu ◽  
Isabelle Romieu ◽  
Min Shi ◽  
Dana B. Hancock ◽  
Huiling Li ◽  
...  

2018 ◽  
Vol 19 (10) ◽  
pp. 3145 ◽  
Author(s):  
Jie Yu ◽  
Weiguo Zhao ◽  
Wei Tong ◽  
Qiang He ◽  
Min-Young Yoon ◽  
...  

Salt toxicity is the major factor limiting crop productivity in saline soils. In this paper, 295 accessions including a heuristic core set (137 accessions) and 158 bred varieties were re-sequenced and ~1.65 million SNPs/indels were used to perform a genome-wide association study (GWAS) of salt-tolerance-related phenotypes in rice during the germination stage. A total of 12 associated peaks distributed on seven chromosomes using a compressed mixed linear model were detected. Determined by linkage disequilibrium (LD) blocks analysis, we finally obtained a total of 79 candidate genes. By detecting the highly associated variations located inside the genic region that overlapped with the results of LD block analysis, we characterized 17 genes that may contribute to salt tolerance during the seed germination stage. At the same time, we conducted a haplotype analysis of the genes with functional variations together with phenotypic correlation and orthologous sequence analyses. Among these genes, OsMADS31, which is a MADS-box family transcription factor, had a down-regulated expression under the salt condition and it was predicted to be involved in the salt tolerance at the rice germination stage. Our study revealed some novel candidate genes and their substantial natural variations in the rice genome at the germination stage. The GWAS in rice at the germination stage would provide important resources for molecular breeding and functional analysis of the salt tolerance during rice germination.


2019 ◽  
Author(s):  
Waltram Ravelombola ◽  
Jun Qin ◽  
Ainong Shi ◽  
Fengmin Wang ◽  
Yan Feng ◽  
...  

Abstract Background Soybean [ Glycine max (L.) Merr.] is a legume of great interest worldwide. Enhancing genetic gain for agronomic traits via molecular approaches has been long considered as the main task for soybean breeders and geneticists. The objectives of this study were to evaluate maturity, plant height, seed weight, and yield in a diverse soybean accession panel, to conduct a genome-wide association study (GWAS) for these traits and identify SNP markers associated with the four traits, and to assess genomic selection (GS) accuracy. Results A total of 250 soybean accessions were evaluated for maturity, plant height, seed weight, and yield over three years. This panel was genotyped with a total of 10,259 high quality SNPs postulated from genotyping by sequencing (GBS). GWAS was performed using a Bayesian Information and Linkage Disequilibrium Iteratively Nested Keyway (BLINK) model, and GS was evaluated using a ridge regression best linear unbiased predictor (rrBLUP) model. The results revealed that a total of 20, 31, 37, 31, and 23 SNPs were significantly associated with the average 3-year data for maturity, plant height, seed weight, and yield, respectively; some significant SNPs were mapped into previously described loci ( E2 , E4 , and Dt1 ) affecting maturity and plant height in soybean and a new locus mapped on chromosome 20 was significantly associated with plant height; Glyma.10g228900 , Glyma.19g200800 , Glyma.09g196700 , and Glyma.09g038300 were candidate genes found in the vicinity of the top or the second best SNP for maturity, plant height, seed weight, and yield, respectively; a 11.5-Mb region of chromosome 10 was associated with both seed weight and yield; and GS accuracy was trait-, year-, and population structure-dependent. Conclusions The SNP markers identified from this study for plant height, maturity, seed weight and yield can be used to improve the four agronomic traits through marker-assisted selection (MAS) and GS in soybean breeding programs. After validation, the candidate genes can be transferred to new cultivars using SNP markers through MAS. The high GS accuracy has confirmed that the four agronomic traits can be selected in molecular breeding through GS.


2020 ◽  
Vol 10 (5) ◽  
pp. 1671-1683 ◽  
Author(s):  
Meng Lin ◽  
Susanne Matschi ◽  
Miguel Vasquez ◽  
James Chamness ◽  
Nicholas Kaczmar ◽  
...  

The cuticle, a hydrophobic layer of cutin and waxes synthesized by plant epidermal cells, is the major barrier to water loss when stomata are closed at night and under water-limited conditions. Elucidating the genetic architecture of natural variation for leaf cuticular conductance (gc) is important for identifying genes relevant to improving crop productivity in drought-prone environments. To this end, we conducted a genome-wide association study of gc of adult leaves in a maize inbred association panel that was evaluated in four environments (Maricopa, AZ, and San Diego, CA, in 2016 and 2017). Five genomic regions significantly associated with gc were resolved to seven plausible candidate genes (ISTL1, two SEC14 homologs, cyclase-associated protein, a CER7 homolog, GDSL lipase, and β-D-XYLOSIDASE 4). These candidates are potentially involved in cuticle biosynthesis, trafficking and deposition of cuticle lipids, cutin polymerization, and cell wall modification. Laser microdissection RNA sequencing revealed that all these candidate genes, with the exception of the CER7 homolog, were expressed in the zone of the expanding adult maize leaf where cuticle maturation occurs. With direct application to genetic improvement, moderately high average predictive abilities were observed for whole-genome prediction of gc in locations (0.46 and 0.45) and across all environments (0.52). The findings of this study provide novel insights into the genetic control of gc and have the potential to help breeders more effectively develop drought-tolerant maize for target environments.


Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 732 ◽  
Author(s):  
Zhang ◽  
Chen ◽  
Ye ◽  
He ◽  
Huang ◽  
...  

In the pig industry, reproductive traits constantly influence the production efficiency. To identify markers and candidate genes underlying porcine reproductive traits, a genome-wide association study (GWAS) was performed in a Duroc pig population. In total, 1067 pigs were genotyped using single-nucleotide polymorphism (SNP) chips, and four reproductive traits, including litter size at birth (LSB), litter weight at birth (LWB), litter size at weaning (LSW), and litter weight at weaning (LWW), were examined. The results showed that 20 potential SNPs reached the level of suggestive significance and were associated with these traits of interest. Several important candidate genes, including TXN2, KCNA1, ENSSSCG00000003546, ZDHHC18, MAP2K6, BICC1, FAM135B, EPHB2, SEMA4D, ST3GAL1, KCTD3, FAM110A, TMEM132D, TBX3, and FAM110A, were identified and might compose the underlying genetic architecture of porcine reproductive traits. These findings help to understand the genetic basis of porcine reproductive traits and provide important information for molecular breeding in pigs.


2020 ◽  
Author(s):  
Marc Rickenbacher ◽  
Céline S Reinbold ◽  
Stefan Herms ◽  
Per Hoffmann ◽  
Sven Cichon ◽  
...  

Abstract Background: Postoperative cognitive dysfunction (POCD) is a common neurocognitive complication after surgery and anesthesia, particularly in elderly patients. Various studies have suggested genetic risk factors for POCD. The study aimed to detect genome-wide associations of POCD in older patients.Methods: In this prospective observational cohort study, participants aged ≥65 years completed a set of neuropsychological tests before, at 1 week, and 3 months after major noncardiac surgery. Test variables were converted into standard scores (z-scores) based on demographic characteristics. POCD was diagnosed if the decline was >1 standard deviation in ≥2 of the 15 variables in the assessment battery. A genome-wide association study (GWAS) was performed to determine potential alleles that are linked to the POCD phenotype. In addition, candidate genes for POCD were identified in a literature search for further analysis.Results: Sixty-three patients with blood samples were included in the study. POCD was diagnosed in 47.6% of patients at 1 week and in 34.2% of patients at 3 months after surgery. Insufficient sample quality led to exclusion of 26 patients. In the remaining 37 patients, a GWAS was performed, but no association (P < 5*10-8) with POCD was found. The subsequent gene set enrichment analysis of 34 candidate genes did not reveal any significant associations.Conclusion: In this patient cohort, a GWAS did not reveal an association between specific genetic alleles and POCD at 1 week and 3 months after surgery. Future genetic analysis should focus on specific candidate genes for POCD.Trial registration: ClinicalTrials.gov (NCT02864173)


2021 ◽  
Author(s):  
Taeko Shibaya ◽  
Chika Kuroda ◽  
Hisano Tsuruoka ◽  
Chiharu Minami ◽  
Akiko Obara ◽  
...  

Abstract Carrot is a major source of provitamin A in a human diet. Two of the most important traits for carrot breeding are carotenoid contents and root color. To examine genomic regions related to these traits and develop DNA markers for carrot breeding, we performed a genome-wide association study (GWAS) using genome-wide single-nucleotide polymorphisms (SNPs) in two F2 populations, both derived from crosses of orange root carrots bred by a Japanese seed company. The GWAS revealed 21 significant associations, and the physical position of some associations suggested two possible candidate genes. An Orange (Or) gene was a possible candidate for visual color evaluation and the α- and β-carotene contents. Sanger sequencing detected a new allele of Or with an SNP which caused a non-synonymous amino acid substitution. Genotypes of this SNP corresponded to the visual evaluation of root color in another breeding line. A chromoplast-specific lycopene β-cyclase (CYC-B) gene was a possible candidate for the β/α carotene ratio. On CYC-B, five amino acid substitutions were detected between parental plants of the F2 population. The detected associations and SNPs on the possible candidate genes will contribute to carrot breeding and the understanding of carotenoid biosynthesis and accumulation in orange carrots.


Sign in / Sign up

Export Citation Format

Share Document